Guard all log statements with log_enabled().

Checking log.isEnabledFor() once avoids the often expensive repr_command() calls
as well as calls to log.debug() itself. This is a especially large savings in
_execute_{pipeline,transaction}().

Author: whilp

redis/client.py

@@ -58,7 +58,8 @@ def connect(self, redis_instance):
         "Connects to the Redis server if not already connected"
         if self._sock:
             return
-        log.debug("connecting to %s:%d/%d", self.host, self.port, self.db)
+        if log_enabled(log):
+            log.debug("connecting to %s:%d/%d", self.host, self.port, self.db)
         try:
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             sock.settimeout(self.socket_timeout)
@@ -82,7 +83,8 @@ def disconnect(self):
         "Disconnects from the Redis server"
         if self._sock is None:
             return
-        log.debug("disconnecting from %s:%d/%d", self.host, self.port, self.db)
+        if log_enabled(log):
+            log.debug("disconnecting from %s:%d/%d", self.host, self.port, self.db)
         try:
             self._sock.close()
         except socket.error:
@@ -161,6 +163,9 @@ def dict_merge(*dicts):
     [merged.update(d) for d in dicts]
     return merged
 
+def log_enabled(log, level=logging.DEBUG):
+    return log.isEnabledFor(log, level)
+
 def repr_command(args):
     "Represents a command as a string."
     command = [args[0]]
@@ -338,7 +343,8 @@ def _execute_command(self, command_name, command, **options):
         if self.subscribed and not subscription_command:
             raise RedisError("Cannot issue commands other than SUBSCRIBE and "
                 "UNSUBSCRIBE while channels are open")
-        log.debug(repr_command(command))
+        if log_enabled(log):
+            log.debug(repr_command(command))
         command = self._encode_command(command)
         try:
             self.connection.send(command, self)
@@ -1438,7 +1444,7 @@ def _execute_transaction(self, commands):
             commands,
             (('', ('EXEC',), ''),)
             )])
-        if log.isEnabledFor(logging.DEBUG):
+        if log_enabled(log):
             log.debug("MULTI")
             for command in commands:
                 log.debug("TRANSACTION> "+ repr_command(command[1]))
@@ -1468,7 +1474,7 @@ def _execute_transaction(self, commands):
     def _execute_pipeline(self, commands):
         # build up all commands into a single request to increase network perf
         all_cmds = ''.join([self._encode_command(c) for _1, c, _2 in commands])
-        if log.isEnabledFor(logging.DEBUG):
+        if log_enabled(log):
             for command in commands:
                 log.debug("PIPELINE> " + repr_command(command[1]))
         self.connection.send(all_cmds, self)